This SCOR program continues its commitment to the development of a relevant scientific data base which will lead to the prevention and control of acute and chronic lung injury induced by exposure to workplace inhalants. Population-based studies, emphasizing the detection of exposure-response relationships and their modifiers, lead to new knowledge regarding the determinants of these lung effects. In vitro and animal exposure studies refine the ability to detect these relationships and further intervention in the disease processes studied is the desired product of this basic research. The research described in this proposal is possible only through the interdisciplinary synergy which has developed among pulmonary physician-investigators, immun- ologists and cell biologists, epidemiologists and statisticians, industrial hygienists and bioengineers. Regular interaction is made possible by contiguous laboratories and other facilities available to the SCOR program. Processing and analysis of very large data sets are facilitated by the availability of state of the art computer hardware and software. While continuing the program's long interest in the full spectrum of occupational causes of lung disease, this proposal reflects an appropriate change in emphasis toward a better understanding of acute and long-term injury produced by accidental and prevailing exposures to irritant gases and chemical vapors. Balance is carefully maintained between human observations, animal model experiments and laboratory "bench" research. The projects, which deal with animal and human responses to chemical injury, tissue fate of man-made mineral fibers, mechanisms of toxic gas- mediated lung injury, fibrogenesis, and relationships between alveolar and interstitial cells in the pathogenesis of interstitial lung disease, exemplify this balance.